Safety paper



Patented Apr. 26, 1927.

UNITED STATES JOHN GENOESE, OF SAN FRANCISCO, CALIFORNIA.

SAFETY PAPER.

No Drawing.

The invention relates to a safety paper for use as checks and other negotiable instruments, which paper is constructed to disclose alterations of the names or figures written on the check.

Safety papers for this purpose have been largely used by the banks, for the purpose of preventing or 'minimizing check alterations. These safety papers have usually comprised a sheet of paper coated with a material which bleaches out when an ink cradicat-or is applied to the surface of the check, thereby indicating that the check has been tampered with. In the various safety papers with which I am familiar, the application of the ink eradicator merely bleaches the coating on the paper and, when this coating is very light in color, the bleached spot is sometimes barely perceptible. Further, the bleached spot may be readily covered by an expert check raiser with a brush and water color, duplicating the color and design of the protective coating on the check.

In accordance with my invention, I provide a safety paper, which, when an ink eradicator is applied thereto, produces a dark spot, which cannot be removed, thereby clearly indicating an effort to alter the check.

An object of my invention, therefore, is to provide a safety paper which, when treated with an ink eradicator, will cause the production of a dark spot, so that the check may not be altered.

In accordance with my invention, I prefer to first treat or impregnate the paper with a material which, when treated with the bleaching agent of the ink eradicator, will produce a spot, and then to coat the surface of the paper with a material which will also produce a dark spot upon the application of the ink bleach. so that the dark spot produced by the ink bleach, extends entirely through the paper, so that it may not be removed.

In accordance with my invention, therefore, I first prepare the paper treating fluid and I shall set forth one form of treating fluid with which I have secured excellent results.

To 42 ounces of water I have added 3% ounces ofalcohol (denatured alcohol), 1% ounces of finely divided lead carbonate, and 1 ounce of finely divided zinc sulphide. This mixture is heated gently for about one-half Application filed November 22, 1924. Serial No. 751,683.

hour and then ounce of sodium bromide is added to the mixture. The resulting fluid is then strained and the paper is immersed in it and permitted to dry. The zinc sulphide and the lead carbonate serve to prevent the applied ink from spreading and he sodium bromide produces a yellowishblue mark in the paper when the ink eradicating bleach is applied thereto.

The dried paper is then treated or partially coated with a material having the general characteristics of an ink and this material is preferably applied to the surface of the paper by plates in a printing press, so that a design is imprinted on the surface of the paper. The ink is preferably light in color, so that a contrast is presented by the applied ink when the check is written.

I have had excellent results with a coating material consisting of 2 pounds of glycerine, 2 pounds of glucose, 1% ounces of zinc sulphate, 8 ounces of dry magnesia, ounce resublimed iodine, and 3 ounces of nickel chloride, all by weight. To this mixture I add a small amount of a suitable dye, depending upon the desired color of the coating to be produced. This mixture is then heated until it becomes substantially homogeneous and I then add 12 ounces of alcohol, which is stirred well into the mixture. The mixture is then permitted to cool and stand for a short time, after which it is ready for use.

The glycerine and the glucose give the material the necessary adhesive properties, so that it will properly adhere to the paper. The dry magnesia is added to give the material the necessary body, so that it may be applied to the paper by printing plates. The

iodine in the mixture serves to produce a blue mark or spot when the ink eradicator bleach is applied to the coated paper. The nickel chloride produces a green mark or spot when the ink eradicator bleach is applied to the paper. The zinc sulphate serves to make the marks or spots darker, so that a very dark spot is produced, which penetrates the paper. lVhen desired, the iodine may be omitted and, under these circumstances, the spot produced will be greenish and, if the nickel chloride is omitted, the spot will be blue. I find, however, that better results are obtained by including all of the ingredients set forth, since the spot produced thereby is very dark in color and cannot be erased or obliterated. By the use oi these materials I have produced i safety paper, to. which the application of an ink eradicator produces a dark spot Which penetrates the paper, thereby clearly indithe figures or letters which have been Written onto the paper.

I claim: 1. A safety paper comprising a sheet of 10 paper treated with a mixture containing :1 eating that an effort has been made to alter sodium bromide, and with a mixture of zinc sulpl'late, nickel chloride; and iodine.

2. A safety paper comprising a sheet of paper treated With a mixture of zinc sulphide, lead carbonate and sodium bromide, and with a mixture containing z'inc sulphate, nickel chloride and iodine.

In testimony whereof, I have hereunto: set

my hand.

JOHN GENOESE. 

